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WSU/Pend Oreille Extension introduced the Sense of Place series in 1999, with a focus on place-based stewardship education. Since 2001, a partnership with the Kalispel Tribe of Indians Natural Resources Department (KNRD) has supported this newsletter and allowed us to expand class offerings through EPA funding. Further staff support comes through Renewable Resources Extension Act (RREA). Many thanks to our partners and to you, our readers, for your continued enthusiasm for "digging" into the natural history and culture of this part of the world.

Fish Doctor

by Jack Nisbet • Author and historian
illustrations by Emily Nisbet

For anyone interested in what northeastern Washington looked like when the first white fur traders entered the region, one of the hardest aspects to imagine is the water. Columbia River tributaries like the Pend Oreille and Clark Fork rivers seems hopelessly obscured by layers of mining and forest management practices, introduced sport species and commercial-scale hatcheries, all manner of irrigation projects and the construction of gigantic dams. But there are ways to peer into the past, and one researcher who tries to provide some perspective on large-scale discussions of the Columbia drainage is Dr. Virginia Butler of Portland State University. Working at the opposite end of the time line from modern fish biologists, Dr. Butler’s publications raise intriguing questions about the age-old relationship between humans, water, and fish.

Butler studies the fish bones from archaeological sites dating back to the end of the last Ice Age. She has learned how to separate natural back eddies of accumulated fish bones from the kitchen deposits known as middens, and crunched numbers to gauge the utilization of fish resources by people living their daily routine. Building on these data, her reports provide baseline knowledge about drainage dynamics, climate fluctuation, resource utilization, and the influence of human pressure on a confined population—exactly the kinds of issues at the forefront of river politics today.

Along an eastern Washington salmon stream where successive human occupations spanned several thousand years, Butler analyzed the fish bones left behind at a group of closely associated rock shelters. Archaeologists working in the deeper, more ancient strata within these shelters (dating back to around 4,000 years before the present) found the remains of entire salmon, including head and pectoral fin elements. In shallower, more recent strata (1-2,000 years old), extensive middens contained only salmon vertebrae and pelvic fins. Why the difference?

Butler explains that salmon heads contain more fat than salmon bodies. They require a longer drying time, and more heat and labor to preserve. This means that if salmon are meant to be stored for the long term, it is more efficient to separate the heads from the bodies. Thus in the older layers where entire salmon appear, it seems likely that people were consuming whole roasted fish soon after they caught them. In contrast, the more recent layers contained exactly the bones that would be left behind if butchers removed each fish’s head and processed the bodies at a separate location. The kitchen middens at these rock shelters thus may trace the crucial transition from a mobile hunting and gathering society to one that could store food and remain sedentary for an entire winter.

But such a revelation only leads to deeper questions about the presence of the fish. What did such mountain streams, small rivers, and the upper Columbia itself look like at the end of the Pleistocene ice age? How long did it take salmon and other species of fish to reestablish their spawning patterns in drainages that had been blocked by ice? Which of the several salmon species came upriver first? How did long-term cycles of temperature and rainfall affect the mix of species in any particular river or stream? Could people have any influence over the composition or success of such salmon runs? The answers to such questions are all under discussion, and plant pollen counts, careful archaeological digs, and a growing body of meteorological evidence provide some good clues.

If you take the end of the Pleistocene as around 12-13,000 years ago (the latter date is close to the accepted time of the last Lake Missoula flood), northeastern Washington fish had to spend centuries working their way back up streams that had been closed off by ice. Even after the first whitefish, minnows, and suckers had reestablished themselves, it took a lot more time to develop the huge salmon populations that the main stem of the Columbia and certain of its tributaries are legendary for—those epic runs that fueled many different aspects of the larger ecosystem, including large tribal fisheries like the one at Kettle Falls.

Global temperatures and the composition of local vegetation underwent considerable flux between 4000 and 1000 years before the present, but archaeological sites indicate salmon streams were consistently productive during that period. The bones left behind are far from uniform, however, and Dr. Butler describes a noticeable difference in the size of salmon vertebrae between some of the older strata of one Cascade stream, dating back past 3000 years before the present, and more recent layers: whoever lived at the older site was eating significantly larger fish.

Butler and associates that include Harriet Huber of the NOAA marine Mammal Laboratory in Seattle have worked to develop a method for identifying salmon species through a series of measurements on single vertebrae. These measurements indicate that the larger fish bones from the older site contained more chinook (king) and coho (silver) salmon, while the smaller bones from the more recent strata were weighted toward sockeye salmon and steelhead or rainbow trout. And what does that mean? Could subtle changes in climatic patterns or ocean food sources have tilted the balance toward the smaller fish? Could a geological event, such as a landslide or earthquake, have changed something about the river conditions? Could human fishing patterns, which naturally would focus on larger chinooks (every fisherman likes to brag about the size of their catch) have skewed the ratio toward the smaller species?

At the moment we can only guess. But the more fish middens that Dr. Butler sifts through, the more information we will have that might prove useful when considering the next dam removal or fish introduction, the impact of large-scale water impoundment, or the possible long-term impacts of global warming. Her work should encourage everyone to look at the long scale of time.

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